Inductor-generator.



1. L. MILTON. INDUCTOR GENERATOR.

APPLICATION FILED IULYIG, |907- RENEWED APR. 29.1914- Patented June 1, 1915.

` 1,1. MLmN. INDUCTOR GENERATOR.

APPLICATION FILED IULY, 190?. RENEWED APR. 29, H314.

1 1 4; 1 ,4:74, Patented J une 1, 1915.

2 SHEETS-SHEET 2.

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4b @5b A Q 5 Wni 5555 InVS UTET l 'if TIFl-LEQE JOHN L. MILTON, 0F CHICAGO, ILLINOIS, ABSIGNOR, BY MESNE ASSIGNMENTS, TO WEBSTER ELECTRIC COMPANY, RACINE, WISCONSIN, A CORPORATION 0F WEST VIRGINIA.

INDUCTORrG'ENERATOB.

Specication of Letters Patent.

rammed June i, i915.

Application filed July 16, 1907, Serial No. 384,049. Renewed April 29, 1914. Serial No. 835,332.

T0 all 'whom it may concern:

Be it known that I, JOHN L. MILTON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Inductor-Generators, ofV which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to inductor-alternators. It pertains particularly to electric generating apparatus of the inductor-alternator type adapted for use in ignition systems and for purposes of similar requirement.

One of the objects of the invention is to construct, with relatively few parts having a simple and compact arrangement, a magneto or electric generator for use in connection with ignition systems for internal combustion hydrocarbon motors and for other purposes requiring`electromotive force capable of producing powerful eHects.

In the accompanyingdrawings, purpose. of illustration, I have shown an embodiment of my invention in an inductoralternator particularly adapted for "use in high tension ignition systems for internal combustion motors, it being understood that my invention is likewise applicable for low tension work.

-Figure l is a front elevation of an apparatus embodying my invention; Fig. 2 is a section on line 2 2 of -ig. 1; Fig. 3 is a diagrammatic view show ng the parts of the apparatus in one relation to each other; Fig. 4 is a diagrammatic view showing the parts of the apparatus in a different relationV tov each other; and Fig. 5 is a diagram matic view of an apparatus embodying a modification.

Referring to the drawings, 1 indicates as an entirety a usuitable field-magnet frame. It is preferably made up of two field magnets 2 and 3, oppositely disposed and having their j like poles joined by magnetic connecting pieces 4 and 5, respectively. By

members or l each magnet 1s composedv of a preference,

group of permanent straight-bar magnets 6,

ings each pole piece is though electromagnets may be employed instead of permanent magnets if desired.

In the construction shown in the drawnotched or cut away at either end, as indicated at 7, to receive the for the i adjacent ends of one group of permanent magnets placed side by side vertically and in engagement'with the ledge 7 of said cut-v away portion. l

A U-shaped clip 8 straddles the end of a pole piece and the end of the group of permanent magnets adjacent thereto. The clips are secured in position to the pole piece by a rivet 8 or in any other suitable manner. Each connecting member carries a pair of polar projections, those on the connecting member 4 being indicated by 4 and 4a, while those on the connecting member 5 are indicated by 5 and 5a. Between each pair of polar projections is a connecting portion 4" and 5", respectively, which serves`as the core for the windingmounted between the polar projections on one or both of the connecting members.

In Fig. 1, coils 9 and l() of insulated Wire surround the cores 4b and 5b respectively and constitute the primary windings. Coils 11 and 12 of insulated wire surround the primary windings 9 and 10, respectively, and constitute the secondary windings. relative sizes of wires in the4 primary and secondary windings, together with the number of turns in said windings, may be varied in accordance with the results desired from the apparatus and the purposes for which it is constructed.

In the embodiment of my invention illustrat'ed in the drawings, the polar projections carried by the connecting members are turned' inwardly, and each has a polar face curved in the arc of a .circle struck from the axis of the field-magnet frame as a center. The axis of the inductor shaft is coincident withthe axis ot' the field-magnet frame. An unwound inductor 14 is carried by the shaft 13 and arranged to 'rotate between the polar faces of the diametrically opposite polar projections. The curved end surfaces of the inductor are made to operate as closely adjacent to the polar faces on the The by a bearing standardi 16. The supporting and bearing plate 17 ofnon-magnetic material has an annular extension 17 preferably mounted upon the extended end 15 of the bearing 15. This plate 17 carries four radially extending arms 17a, veach of which is suitably connected at its outer end to the adjacent inner end of one of the polar projections of the field-magnet frame. A set screw 18 permits securing the magnet frame 1 in any desired position of angular adjustment relative to the inductor shaft 13 for the purpose of varying the moment of generation of maximum electromotive force of which the apparatus is capable relatively to the position of a piston within the engine cylinder, or, in other words, angularly adjusting the magnet frame to accommodate the apparatus for spark-retarding or spark-advancing in the engine cylinder. A

The connecting members; polar projections and inductors, are preferably composed of laminac of metal having a high magnetic permeability` and susceptibility.

The coils of the primary and secondary windings on the connecting members 4. and 5 in the construction shown in Fig. 1 may be connected up electrically in any desired manner. I have shown the coils of both sets of windings electrically connected in series by suitable conductors 9 and 11', the former connecting the primary coils 9 and 10 and the latter connecting the secondary coils 11 and 12.- At l18L and 12a are indicated the terminals of the secondary circuit on the generator. A condenser 19 is interposed in the primary circuit for the purpose of increasing the electromotive force induced by the apparatus, by assisting in accelerating the break or interruption of current in the primary coils at the instant when `it is desired to have a high electromotive force in the secondary coils,-all as will be understood by those skilled in the art.

One terminal of the condenser is connected by an electric conductor 20 to the element 2l of a suitable current-interrupting device 22 interposed in the circuit of the primary windings. This element 21 carries a suitable-make-and-break point, not shown. An electric conductor 23 connects the element 21 with the primary windings of the apparatus. A second element 21 of the inter- `rupter is suitably insulated at one end from the adjacent end of the element 21, and is at its other end provided with a make-andbreak point adapted to be moved into and out of contact with the point on the element timing cam or timer 24 causes, at predetermined intervals, the separation of the makeand-break points and the consequent break or interruption of the primary circuit. It should be operated synchronously with the inductor 14. `For purposes of illustration I have shown the timer carried by and otating with the inductor shaft 13.

The timer 24 should operate to permit or cause the interruption of the electric circuit at the instant of maximum variation of magnetic flux density in the induction windings on the connecting members or pole pieces, as they may also be called. lVhen the magnet frame is angularly adjusted for the purpose of varying the moment of generation of maximum electric force relatively to the position of the piston in the cylinder, I have found it of advantage to have the current interrupter 22 adjustable simultaneously with the field-magnet frame, in order toaccomplish the results desired in advancing or retarding the spark in the engine cylinder. For this purpose I have loosely mounted an angularly adjustable collar 25, which carries the make-and-break elements 21 and 21 upon the bearing standard 16, and have suitably connected it to the angularly adjustable supporting plate 17 by means of a cross-connecting member 26 secured at one end to the plate 17 and at its other end to the collar 25. IVith this larrangement of parts, if the magnet frame is adjusted for the purpose of variation of the molnent of generation of maximum electromotive force, the circuit interrupter is simultaneously adjusted so that the timer 21 will continue to interrupt the circuit at the instant of-maximum variation of magnetic fiux density in the induction windings of the generator. The capacity of the condenser 19 is suitably related to the selfinduction of the primal-:y circuit and thel ra )idity of operation of the interrupter 22.

he inductor 14, which may be either rotated or oscillated, -as desired, serves, by its movements relativelyA to the polar faces on the polar projections, to establish substantial magnetic short-circuits for the field magnets, first across one pair of diametrically opposite polar projections and then across the other pair of diametrically opposite polar projections.

The field magnets establish between them `what may be considered a compound magnetic field, in which the lines ofmagnetic force ema'nating from vone magnet. oppose those emanating from the other,l the lines of force from both passing in substantially the. same direction between the pole pieces at either end of the magnet frame. The arrangement of the field magnets and the shape and correlation of the connecting members, the olar projections carried thereby, and the Inductor, is preferably such that in anyr position into which the inductor may be turned it establishes two paths of substantially equal magnetic reluctance, one for the lines of magnetic force set up by one field magnet and the other for the lines of magnetic force set up by the other field magnet.

The electromotive force generated by the apparatus bears a relation to the rapidity of variation of magnetic flux density through the induction windings, as well as to the magnitude of such variation. lVhen the inductor 14 is in the position shown in Fig. 3 a substantial magnetic short-circuit of substantially uniform reluctance for both field magnets is established through the inductor 14 and across the polar projections 4 and 5a. For the purpose of description we may assume the direction of the lines of magnetic force through the inductive windings as indicated by the arrows in Fig. 3.- VVhen the inductor 14 is rotated in either direction from its position shown in Fig. 3, a variation of magnetic flux density through the induction windings is effected, the lines of magnetic force tending to seek thepath of least resistance. The path through the inductor 14 and across the polar projections 4 and 5a increases in reluctance more or less gradually, until the ends of the inductor leave said polar projections and airgaps are established between the ends of the inductor and the polar faces of said polar projections, at which instant the rate of variation of magnetic fiuX density through the inductive windings is very great. The inductor then establishes a substantial magnetic short-circuit of practically uniform reluctance for both field magnets across the polar projections 4aL and 5, and at the same instant reverses the direction of the lines of magnetic force through the inductive windings, the direction of the magnetic fiux being assumptively indicated b v the arrows in Fig. 4. Sudden changing of the direction of the lines of force through the inductive windings at substantially the instant of the greatest variation of magnetic flux density through said windings, induces an electronlotive force in the windings capable of very powerful effect.`

In order to obtain a very pronounced variation in magnetic fiux density and consequently very powerful electronxotive force, from an apparatus of the class herein described, I have so shaped and correlated the polar faces of the polar projections and the cooperating end surfaces of the inductor that as the ends of the inductor leave the polar faces of a pair of diametrically opposite polar projections, air-gaps are caused to exist between the inductor and the polar faces of all the polar projections. Immediately thereafter the inductor establishes a magnetic short-circuit across another pair of diametrically opposite polar projections, thereby effecting a sudden and substantially complete shifting of the lines of magnetic force of the compound magnetic field. For this purpose I have made the width of the inductor across its curved end surfaces less than the distance between the most closely adjacent points of the polar faces on any two polar projections. This last referred-to correlation of the polar projections and the inductor is described for the purpose of illustrating one construction of apparatus embodying my invention. By making the width of the inductor across its curved end surfaces greater than the distance between any two adjacent polar projections the magnetic circuit is substantially closed at all times.

In Fig. 5 I have shown an inductor-alternator embodying my invention with a' slightly modified form of inductor, the polar faces being suitably shaped and.correlated to the inductor. In this apparatus the inductor consists of a disk 30, the periphery of which is studded with teeth 3l uniformly spaced apart. The inner ends of the polar projections are toothed to correspond with the toothed periphery of the inductor, the teeth on the diametrically opposite pairs of polar projections being disposed so as to register with a corresponding number of teeth on the inductor to establish substantial magnetic short-circuits through the inductor across the said polar projections. The teeth on the polar projections 4 and 5 are disposed about the periphery of the inductor 30 in such manner that when the inductor establishes a magnetic short-circuit across the polar projections 4 and 5 the teeth on these projections register with notches between adjacent teeth on the inductor, so that the magnetic short-circuit is open between the polar projections 4 and 5, as indicated in Fig. 5. In an apparatus having a toothed inductorV and polar projections such as just described, a greater number of changes of direction of the magnetic flux through the inductive windings is effected at a given speed of rotation, and consequently a greater number of impulses of electromotive force is induced, than with the form of inductor shown in the other figures when rotated at the same speed.

lVhat I claim is:

l. In an inductor-alternator, the combination of two permanent straight-bar magnets, a pair of magnetic members secured at their ends to said magnets for connecting poles of like polarity and forming with said magnets a substantially rectangular field-frame, two polar projections on each of said magnetic members, unlike polar projections heilig arranged in diametrieally opposite pairs, generating windings carried bv said magnetic members between the polar projections thereof, and a movable inductor for establishing a magnetic short-circuit first through one pair and then through the other pair of diametrically opposite polar projections so that the magnetic lines of force may travel first in one direction and then in the other through said generating windings.

2. In an inductor-alternator, the combination of' oppositely disposed field-magnets, a pair of magnetic members arranged at right angles to said field magnets for connecting poles of like polarity, two polar projections on each of said magnetic members, unlike polar projections being arranged in diametrically opposite pairs, generating windings carried by said magnetic members between the polar projections thereon, and a movable inductor constructed to span first one pair and then the other pair of diametrically opposite polar projections for simultaneously reversing the direction of the magnetic fiux through said windings.

In an inductor-alternator, the combination of a magnetic field structure provided with magnetic connecting members between poles of like polarity, two polar projections on each of said magnetic connections, generating windings carried by said connections between the polar projections thereof, and an inductor movable in the plane of the field structure for periodically reversing the direction of' the magnetic fiux simultaneously through said windings.

4. In an inductor-alternator. the combination of two permanent straight-bar inagiiets, a pair of magnetic members secured at their ends to said magnets for connecting poles of like polarity and forming with said magnets a substantially rectangular field frame, two polar projections carried by each of said magnetic members, unlike polar projections being arranged in diametrically opposite pairs, generating windings on said magnetic members between the polar projections thereof, and an inductor movable in the plane of the field structure for periodically reversing the direction of the magnetic flux simultaneously through both windings.

5. In an indactor-alternator, the combij nation of two permanent straiglit-bar magnets, a pair of' magnetic pole members secured at their ends to said magnets for connecting poles of' like polarity and forming with said magnets a substantially rectangular field frame, one of said magnetic pole members being provided with two projections, a ,generating winding carried b v the part of said last-meiitioiied magnetic niember connecting said projections, and a movable iiiductor for establishing a magnetic short-circuit through one and then the other of said polar projections and the opposite magnetic polar member of the rectangular field frame so that the magnetic lines of force may travel first in one direction and then in the other through said generating winding.

6. In combination with a permanently magnetic field structure, a generating winding, a single laminated core of magnetic material upon which said winding is mounted in inductive relation thereto, pole pieces for said core located on each side of said generating winding, and a movable element operable in proximity to said pole pieces cooperating with the field structure to direct the magnetic flux through said core in one direction and then direct the flux through said core in the opposite direction to reverse the direction of the current induced in said winding.

7 In combination, a structure of magnetic material constituting a core, a pair of pole faces for said core, a generating winding in inductive relation to said core and disposed on the core between said pole faces, a permanently magnetic field structure, and a movable element operable in proximity to said pole faces cooperating with the field structure to direct magnetic flux through the core in one direction and then in the opposite direction to reverse the direction of the current generated in said winding.

8. In combination, a laminated structure constituting a core, a generating winding located on said laminated core structure intermediate its ends. a permanently magnetic field structure,` and an inductor operable in proximity to the ends of said laminated core structure cooperating with the field structure to direct the magnetic flux through said laminated core structure in one direction and then in the opposite direction to cause a reversal of direction of the current generated in said winding.

f). A magneto of' the class described, comprising in combination a core of magnetic material, a generating winding disposed on said core intermediate its ends, a perinaiiently magnetic field structure, and an element operable in proximity to the ends of said core cooperating with the permanently magnetic field structure to direct the magnetic flux through said coi'e in one direction and then in the opposite direction to reverse the direction of the current generated in said winding.

10. In combination with a permanently magnetic field structure, a generating winding, a single core of magnetic material upon which said winding is mounted in inductive relation thereto, pole pieces for said core located on each side of said generating winding. and a movable element operable in proximity to said pole pieces cooperating with the permanently magnetic field structure to direct the magnetic flux through said core in one direction and then direct the fiux through said core in the opposite direction to reverse the direction of the current induced in said winding.

11. An alternator of the class described comprising a magnetic core, a generating Winding in inductive relation to said core mounted on the latter intermediate its ends, a permanent magnet normally stationary with respect to said core, and an element operable in proximity to said magnet and the ends of said core coperating with the magnet to direct the magnetic flux through said core in one direction and then reverse the direction of the flux through said core to reverse the direction of the current induced in said winding.

12. In combination with a permanent magnet, a substantially U-shaped core of magnetic material, a generating winding disposed upon and in inductive relation to that portion of the U-shaped core which connects the parallel arms thereof, pole faces formed on the extremities of said parallel arms, and a member movable relatively to the permanent magnet and said pole faces coperating with the permanent magnet to direct the magnetic flux through said core in one direction and then direct the flux through said core in the opposite direction to reverse the direction of the current induced in said Winding.

In testimony whereof I ailix my signature, in presence of two Witnesses.

JNO. L. MILTON. Witnesses:

T. K. WEBSTER, Jr., C. H. NEWMAN. 

